Principles and methods of using several oxygenation methods

1. Chemical oxygenation. It is mainly artificially put some chemical preparation into the aquaculture water body. When it meets water, it chemically acts in the water to release oxygen, thereby increasing the dissolved oxygen content in the water. The chemical oxygenating agent is generally sodium percarbonate, peroxyamide, peroxidation. Oxygenation is one of the important and essential functions of calcium, hydrogen peroxide and peroxodithioammonium. In the production practice, the amount of use is also increasing, especially in the difficulty of power supply, water inconvenience, the mouth of the pond without an aerator, or in the rainy season, sultry, thunderstorm, high temperature, weather changes, floating head hypoxia In cases, this method is used. Ponds with high-density farming methods, especially shrimps such as green shrimp, Macrobrachium rosenbergii, and white shrimp, are prone to hypoxia caused by floating heads in summer. Farmers often keep some chemical oxygenators to prevent accidents. The use of chemical oxygenators mainly takes the whole pool or partial dispersal. The specific dosage depends on the type of the drug and the occasion of use. The farmers should be determined according to the manufacturer.

2. Mechanical oxygenation. The main purpose is to increase the dissolved oxygen in the water by providing a high-quality water body to the aquaculture water through the fishery machinery or by continuously supplying oxygen to the water body through effective contact between the water body and the air. The mechanical oxygenation mode is mainly in the form of water pump, aerator, and oxygenation of the microporous pipe of the blower.

(1) The pump is the traditional auxiliary aeration tool. Mainly when the pump is working, the centrifugal force generated by the impeller in the pump is used to pump water to the pump body to generate a certain pressure of water from the pump outlet. By increasing the contact area between the water and the air, the oxygen in the air is infiltrated. In the water, the oxygen-increasing effect is proportional to the degree of contact between water and air, and also the upper layer water rich in oxygen (the water inlet is too deep into the water layer, the dissolved water is less dissolved in oxygen, and the oxygen-enhancing effect is worse). Water pumping water into the pond should be flushed to the water pump and a water drop plate should be added to the water. On the one hand, it reduces the erosion of water on the pond slope, on the other hand, it expands the contact surface between water and air, and increases the oxygen entering the pond. The specific use method is: change every 15 days in spring and autumn, every 5-10 days in summer high temperature season, change the water a small number of times, take the method of row and then fill, avoid large row and large irrigation, each time change Water accounts for 10%-15% of the pond. Generally, when the water intake time is 1-4, in the rainy morning, depending on the specific conditions, the water is selected to form a certain micro-flow of water in the sunny afternoon to keep the water fresh.

(2) The widely used aerators are impeller and waterwheel. Impeller aerators are the widely used in recent years. During operation, the impeller rotates, the water body is stirred, and the water is generated, and the centrifugal force generated by the rotation causes the upper water body to spread to the periphery, and the lower water body fills the water body to form a water body to circulate up and down. After the surface water with higher oxygen content enters the bottom layer, it effectively improves the dissolved oxygen state of the bottom water body. It is usually used in ponds with a water depth of 1.52 meters. It is mainly used for the cultivation of four major fish such as herring, grass carp, carp, and squid. The impeller-type aeration can meet the oxygenation needs of a 3.8-mu water surface fish pond. The water tanker per kilowatt power basic aerator is to increase the contact between the water and the air to increase the oxygen and promote the flow of water. It is suitable for shallow ponds and is mainly used for green shrimp. , the cultivation of famous premium aquatic products such as P. vannamei. The operation method of the aerator is in accordance with the requirements of “three open and two open”: that is, 2-3 hours of driving at noon on sunny days, 4-5 hours on the next day of cloudy days, and turning on in the middle of the night when the rain is raining or there are signs of floating heads; Boot, do not turn on during the rainy days.